Mandrel stripper for mat winding machine



June 7, 1966 A. 1 M PHERSON ETAL 3,254,366

MANDREL STRIPPER FdR MAT WINDING MACHINE Original Filed Nov. 26, 1957 9 Sheets-Sheet 1 mew/we 0. S75 ve/vs 47 TOKNEYS June 7, 1966 A. M PHERSON ETAL 3,254,366

MANDREL STRIPPER FOR MAT WINDING MACHINE Original Filed Nov. 26, 1957 9 Sheets-Sheet 2 HTTOIQA/Ef;

' June 1966 A. MCPHERSON ETAL 3,254,366

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MANDREL STRIPPER FOR MAT WINDING MACHINE Original Filed Nov. 26, 1957 9 Sheets-Sheet 6 Am 77/1/16 0. STEVE/VJ June 7, 1966 A. L. M PHERSON ETAL 3,254,366

MANDREL STRIPPER FOR MAT WINDING MACHINE Original Filed Nov. 26, 1957 9 Sheets-Sheet 7 #21040 6. JI/LEY HAT/M a. Mal/Ens A. L. M PHERSON ETAL 3,254,366

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3 ka 3 R 5- INVENTOILS EYMXM United States Patent 3,254,366 MANDREL STRIPPER FOR MAT WINDING MACHINE Alexander L. McPherson, Prairie Village, Kans., and

Harold G. Bailey, Akron, and Arthur D. Stevens, Cuyahoga Falls, Ohio, assignors to Gustin-Bacon Manufactnring Company, Kansas City, Mo., a corporation of Missouri Original application Nov. 26, 1957, Ser. No. 698,971, now Patent No. 3,127,024, dated Mar. 31, 1964. Divided and this application June 14, 1963, Ser. No. 298,513

14 Claims. (Cl. 18--2) This application is a division of our copending application Serial No. 698,971, filed November 26, 1957, for a Mandrel Stripper for Mat Winding Machine, now Patent No. 3,127,024, issued March 31, 1964.

Our invention relates to a mandrel stripper for a mat winding machine and more particularly to apparatus for automatically removing a mandrel carrying a cured mat forming a tube of insulation from an oven, stripping the mandrel from the tube of insulation and trimming the ends of the tube.

The copending application of Frederick N. Stephens et al., Serial No. 491,312, filed March -1, 1955, for a Rotary Oven, now Patent No. 2,979,765, issued April 18, 1961, discloses an oven for automatically receiving mandrels wrapped with lengths of a mat or bat of fibrous material impregnated with an uncured resin from a winding machine such as is disclosed in Patent No. 2,742,240, issued April 17, 1956, to Joseph F. Stephens et al. for a Mat Winding Machine. The oven cures the resin and automatically discharges the mandrels carrying the tubes of insulating material formed by the mat windings after the impregnating resin is cured. When the operations performed by the oven disclosed in the copending application are complete, it is necessary that the mandrels be stripped from the tubes of insulation and be returned to the mat winding machine which supplies the oven. Further, it is necessary that the ends of the tubes of insula tion be trimmed to remove excess material from the lengths of insulation. It will be appreciated the operations of removing the wrapped mandrels from the oven, stripping the mandrels from the tubes of insulation and trimming the tube ends, if performed manually, are time consuming and expensive. Manual performance of these operations does not permit advantage to be taken of the potential production capacity of the mat winding machine and rotary oven referred to hereinabove.

We have invented automatic means for removing wrapped mandrels from the curing oven and for conveying them to a mandrel stripper. We have invented a mandrel stripper which automatically receives wrapped mandrels carrying tubes of insulation and which automatically strips the mandrels from the tubes of insulation. Our machine includes means for trimming the ends of the tubes of insulation after the stripping operation has been performed. We provide means for automatically removing stripped mandrels from the stripper and for feeding the removed mandrels to a conveyor which returns the mandrels to the mat winding machine. Our automatic mandrel remover and stripper permits us to take advantage of the high rate of production possible with automatic wrapping and curing machines such as are referred to hereinabove. Our machine permits us to form a greater number of finished tubes of insulating material in a given length of time.

One object of our invention is to provide apparatus for automatically stripping mandrels from tubes of insulating material formed on the mandrels.

Another object of our invention is to provide improved 3,254,366 Patented June 7, 1966 mandrel stripperfor mat winding machines which permits us to take advantage of the potential production capacity of automatic winding machines and curing ovens.

A still further object of our invention is to provide a mandrel stripper for mat winding machines which provides a continuous process for the formation of tubes of insulating material.

Other and further objects of our invention will appear from the following description.

In general our invention contemplates the provision of improved means for removing a wrapped mandrel from the open mold of an automatic curing oven and for feeding the wrapped mandrel to our'mandrel stripper. Our mandrel stripper has pairs of arms mounted at circumferentially spaced locations around a shaft adapted to be stepped to a mandrel stripping station and to a station at which a stripped tube of insulation is delivered to a discharge conveyor. As the shaft is stepped from one station to the other, grippers carried by one pair of arms are actuatedto grasp a tube of insulation carried by a mandrel on the conveyor leading from the curing oven and to move this mandrel to the stripping station. At

the same time, the other pair of arms moves from the stripping to the delivery station and its grippers, which had been closed, open to deliver a stripped tube of insulation to the discharge conveyor. In the course of movement of a stripped tube of insulation from the stripping to the delivery station the ends of the tube are trimmed by the cutters of our apparatus. Between steps of the machine shaft a chuck carried by a movable piston rod moves to grip the end of a mandrel shaft at the stripping station. As the chuck is withdrawn, the grippers retain the tube of insulation while the chuck draws the mandrel out of the tube. When the mandrel has been withdrawn, the chuck is released and automatic unloading arms pick up the mandrel to feed it to a return conveyor leading to the mat winding machine with which our mandrel stripper is used. In order to increase the capacity of our machine we dispose a pair of mandrel strippers in side by side relationship and operate them out of phase to permit two mandrels to be stripped at the same time. We accomplish this last result without wasting floor space.

In the accompanying drawings which form part of the i instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIGURE 1 is a front elevation of our mandrel stripper for mat winding machines showing two stripping units.

FIGURE '2 is a top plan view of the form of our mandrel stripper for mat winding machines taken along the line 2--2 of FIGURE 1.

FIGURE 3 is an end elevation of our mandrel stripper for mat winding machines drawn on an enlarged scale with some parts removed taken along the line 3-3 of FIGURE 1.

FIGURE 4 is a fragmentary sectional view of our mandrel stripper for mat winding machines taken along the line 4-4 of FIGURE 1' and drawn on a greatly enlarged.

scale.

FIGURE 5 is a diagrammatic view of the gripper actuating cams of the units of our mandrel stripper for mat winding machines showing the relative angular disposition of the cam tracks ofthe two units.

FIGURE 6 is a fragmentary sectional view of the mandrel unloader of our mandrel stripper for mat winding machines taken along the line 6-6 of FIGURE 2 and drawn on a greatly enlarged scale.

FIGURE '7 is a fragmentary front elevation of one unit of our mandrel stripper for mat winding machines.

FIGURE 8 is a fragmentary top plan view of one unit of our mandrel stripper for mat Winding machines.

FIGURE 9 is a fragmentary side elevation of our oven unloader used with our mandrel stripper for mat winding machines.

FIGURE 10 is a fragmentary sectional view of the oven unloader of our mandrel stripper for mat winding machines showing the unloader arms in the position occupied when a wrapped mandrel is being deposited on the conveyor and taken along the line 10-10 of FIGURE 9.

FIGURE 11 is a schematic view of one form of control circuit which may be used with our automatic stripper for mat winding machines.

More particularly referring now to FIGURES 9 and 10 of the drawings, as has been explained hereinabove, our mandrel stripper may be used with an automatic curing oven such, for example, as that which is disclosed in the said copending application, Serial No. 491,312. This oven includes a plenum chamber, indicated generally by the reference character 10, with which a plurality of radially extending conduits 12 communicate. The conduits 12 communicate with the interiors of the oven molds carried by casting sections 14, 16 and 18, which sections are hinged together in the manner disclosed in the copending application. As is explained in detail in the copending application the mold sections 16 and 18 are adapted to be moved to an open position by a linkage including a spring 20 connected to section 18, an eye member 22'connected to the spring, a link 24 and a crank 26, carried by a shaft 28 operated by a cam track (not shown) to open the mold after the resin impregnating a tube such as tube 30 carried by a mandrel 32 having shaft ends 34, has been cured. By way of example in FIGURE 9 we have shown one open mold and one closed mold.

Our apparatus for automatically removing a wrapped mandrel, such as mandrel 32, from an open mold includes a pair of arms 34 and 36 carried by a shaft 38 rotatably supported in bearings, one bearing 40 of which is shown in FIGURE 9 mounted on a support 42 located adjacent the oven 10. Any convenient means such as a key 44 or the like secures a crank 46 on the end of shaft 38 outboard of one of the bearings 40 for rotation with the shaft. A pin 48 pivotally connects the end of crank 46 remote from shaft 38 to a piston rod 50 associated with a cylinder 52. A pin 54 pivotally connects the cylinder 52 to a bracket 56 on support 42. Fluid under pressure admitted, in a manner to be described herein after, to cylinder 52 on one side of the piston associated with rod 50 actuates crank 46 to move arms 34 and 36 up toward the open mold. When the flow of fluid to cylinder 52 is reversed in a manner to be described hereinafter, crank 46 drives shaft 38 in the other direction to move the arms 34 and 36 away from the open mold. Respective slots 58 formed in the ends of arms 34 and 36 carry pins 60 which pivotally support latches 62. Springs 64 each have one end disposed in a recess 66 formed in a plate 68 secured to the end of the associated arm. We dispose the other end of each spring in a recess 70 formed in one end of the associated latch 62 normally to urge the latch to rotate its upper end inboard as viewed in FIG- URE 10. As the arms 34 and 36 rotate in a clockwise direction, as viewed in FIGURE 9 under the influence of fluid admitted to cylinder 52, cam surfaces 72 formed on the ends of the latches ride over the mandrel shaft ends 34 to rotate the latches 62 against the action of springs 64. When the arms 34 and 46 have moved the latches over the mandrel shaft ends so that the surfaces 72 no longer are in engagement with the ends 34, the springs 64 position the latches over the mandrel shaft ends. The

direction of flow of fiuid to cylinder 52 is reversed at this time and arms 34 and 36 move in a counterclockwise direction, as viewed in FIGURE 9. In the course of this movement of the arms, latches 62 pull the wrapped mandrel out of the empty mold and onto notches 74 formed in the tops of plates 68. It will be seen that as the arms move in this manner, the wrapped mandrel is carried downwardly, as viewed in FIGURE 9, toward a conveyor, indicated generally by the reference character 76, formed by a pair of spaced pitch chains 78 and 80. A pair of sprocket wheels, one wheel 82 of which is shown in FIGURE 9, are driven in a manner to be described hereinafter to move the chains 78 and in the direction of the arrow A in FIGURE 9. When the wrapped mandrel has been moved down between chains 78 and 80, its ends 34 are positioned in spaced V blocks 84 carried by the chains.

A pair of supports 86 and 88 disposed outboard of chains 78 and 80 carry cam blocks 90 having cam surfaces 92 adapted to be engaged by the lower ends of latches 62, as viewed in FIGURE 10, as arms 34 move downwardly into the respective spaces between chain 78 and support 86 and between chain 80 and support 88. When the lower ends of the latches 62 engage surfaces 92, their upper ends move outwardly of the shaft ends 34, as viewed in FIGURE 10, to release the mandrel shaft ends and permit them to come to rest in V blocks 84 to be carried away from the oven by chains 78 and 80. Guides 94 and 96 carried by a supporting platform 98 support and guide chains 78 and 80 in the course of their movement from the oven to the mandrel stripper to be described hereinafter.

Referring now to FIGURES 1 to 3, the chains 78 and 80 carry the mandrels from the oven 10 to our mandrel stripper, the framework of which is indicated generally by the reference character 100. Chain 78 can be seen in FIGURE 3. As is indicated in the figure, a motor 102 drives a shaft 104 carrying a sprocket wheel 106 and for rotation with the shaft to drive a chain 108 which drives a sprocket wheel 110 fixed on a shaft 112 rotatably supported in a bearing 114 carried by a bracket 116 on the frame 100. Motor 102 provides a drive for the chains 78 and 80.

As has been explained hereinabove, we employ two of our mandrel stripper units, indicated generally respectively by the reference characters 118 and 120 in FIG- URES 1 and 2. By using two of the units and operating them out of phase, we are able to increase the production of the installation at which our strippers are located. When we use two units 118 and 120, it will be clear that two conveyors, each including a pair of chains 78 and 80, are employed to convey wrapped mandrels from two respective ovens 10. Since the units 118 and 120 are substantially identical in detail, for purposes of simplicity only one of the units will be described in detail.

Referring to FIGURES 1 to 4 and 7, respective bearings 122 and 124 carried by supports 126 and 128 of the machine frame rotatably support the main drive shaft 130 of our mandrel stripper. A respective clutch 132 and brake 134 are adapted to be operated in a manner to be described to couple shaft 130 to a shaft 136 driven by any suitable prime mover known to the art. A key 138 fixes a hub 140 carrying a pair of oppositely extending arms 142 and 144 on shaft 130 for rotation with the shaft. Another key fixes the hub of another pair of arms on shaft 130 at a location spaced from the location at which key 138 secures hub 140 to shaft 130. Each unit 118 and 120 has a set of spaced pairs of arms 142 and 144 carried by shaft 130. Since all pairs of arms and their. associated structures are similar, only one pair of arms will be described in detail. We secure stationary grippers 146 and 148 to the ends of the respective arms 142 and 144. Pins 150 and 152 carried by the respective arms 142 and 144 pivotally support respective movable grippers 154 and 156. The grippers of each pair 55 of grippers 154 and 146 and 156 and 148 are so shaped that they may be moved toward each other to grasp a tube of insulation wrapped around a mandrel. As has been explained hereinabove, one arm 142 supports the grippers 146 and 154 at one location on shaft 130, while a second arm 142 axially spaced from the first arm 142 supports another pair of grippers 146 and 154. It is to be understood that the second arm 142 of a unit extends in the same direction from the shaft 130 as does the first arm 142. The hub 140 associated with the secnd arm 142 also carries a second arm 144 having a second pair of grippers 148 and 156.

We provide means for actuating the pairs of grippers 146 and 154 and the pairs of grippers 148 and 156 to close to grasp a tube of insulation carried by a wrapped mandrel and to open to release a tube of insulation from which the mandrel has been stripped at predetermined stations in the course of a revolution of shaft 130. A link 158 pivotally carried by a pin 160 on the movable gripper 154 is pivotally connected by a pin 162 to the end of a crank 164. A key 166 fixes crank 164 on a pivot shaft 168 rotatably supported in an extension 170 formed on hub 140. A second crank 172 supported by shaft 168 for rotation with the shaft carries a cam follower roller 174 disposed in the track 176 of a stationary cam 178. Any convenient means such as brackets 180 may be employed to support the stationary cams 178 on the frame support 126. While we have described only one of the stationary cams 178, it is to be understood that one stationary cam 178 is associated with each of the gripper arm assemblies including the arms 142 and 144.

A pm 182 pivotaly connects one end of a link 184 to the movable gripper 156. A pin 186 connects the end of link 184 remote from pin 182 to the end of a crank 188 fixed on a shaft 190 for rotation with the shaft by means of a key 192. Any convenient means known to the art rotatably supports shaft 190 in an extension 194 on hub 140. A second crank 196 supported by shaft 190 for rotation with the shaft carries a cam follower roller 198 disposed in the track 176 of the stationary cam 178.

In the position of grippers 146 and 154 shown in FIG- URE 4, the linkage including cranks 164 and 172 and link 158 actuates the movable gripper 154 to close the pair of grippers 154 and 146 to the position at which they may grasp a tube of insulation carried by a wrapped mandrel. As shaft 130 rotates in a counterclockwise direction, as viewed in FIGURE 4, track 176 actuates crank 172 through the medium of follower 174 to rotate the crank in a clockwise direction. This rotation of crank 172 rotates crank 164 in a clockwise direction to operate link 158 to move the movable gripper 154 to the open position which is shown as being occupied by movable gripper 156 in FIGURE 4. Also in the course of this movement the actuating linkage for gripper 156 operates the gripper to move it to a position at which it may grasp a tube of insulation carried by a wrapped mandrel.

As can be seen by reference to FIGURE 3 -in the position of the pairs of grippers 146 and 154 and 156 and 148, the pairs of grippers 148 and 156 are in a position to receive a wrapped mandrel 32 as shaft 130 steps in a clockwise direction, as viewed in the figure. In this position of the grippers a wrapped mandrel 32 carried by the conveyor chains 78 and 80 is in a position to be picked up by the stationary grippers 148. As shaft 130 steps through a half revolution in the clockwise direction, as viewed in FIGURE 3, the stationary grippers 148 move up between chains 78 and 80 to pick the wrapped mandrel 32 off the conveyor. As rotation of shaft 130 continues, the movable grippers 156 are actuated to close over the tube 30 of insulation carried by the mandrel 32 firmly to hold the tube in a manner which permits the mandrel 32 to be stripped from the tube. At the same time, the pairs of grippers 146 and 154 has been stripped in a manner to be described open to permit a tube 30 to fall free of the grippers onto a delivery conveyor, indicated generally by the reference character 200, which carries the tube away from the machine. A guide 202 supported from the machine frame in any convenient manner may be employed to ensure that the tube falls onto conveyor 200. From the description advanced hereinabove, it will be clear that two pairs of grippers 146 and 154 and 148 and 156 are offset from the other two pairs of grippers 146 and 154 and 148 and 156. This will be clear from the arrangement pointed out hereinabove which includes two conveyors which are operated out of synchronism with each other.

Referring again to FIGURES 1 and 2, our stripper includes respective piston and cylinder assemblies, indicated generally by the reference characters 204 and 206 which form part of the stripping apparatus of our mandrel stripper. The arrangement of our stripper is such that the assembly 204 is associated with the unit and the assembly 206 is associated with the unit 118.

Referring now to FIGURES 7 and 8, the assembly 204 includes a cylinder 208 and a piston rod 210 to which we secure a pneumatic chuck 212 adapted to grasp the end of a mandrel carried by the pairs of grippers 146 and 154 of the unit 120. We secure a pair of slider bars 214 and 216 to the upper end of a yoke 218 carried by chuck 212. Suitable guides 220 and 222 slidably support rods 214 and 216 on the machine frame to provide additional support for the chuck 212 when piston rod 210 is extended in a manner to be described. As will be explained in detail hereinafter, after shaft completes a stepping operation to position the pairs of grippers 146 and 154 of each unit at a location at which the wrapped mandrel carried by the grippers is in a position to be acted upon by the chuck 212 of the mandrel withdrawing unit 204 or 206 associated with the unit 120 or 118, fluid under pressure is supplied to the cylinder to move the piston rod 210 out of the cylinder to move the chuck 212 toward the unit with which it is associated. As has been explained hereinabove, the assembly 204 is associated with unit 120. We so arrange our machine in order to obviate the necessity of having to draw the mandrels outboard of the units which would require the piston and cylinder units 204 and 206 to be positioned a distance away from the machine, thus requiring more floor space for the installation. As fluid under pressure is supplied to cylinder 208 to drive piston rod 210 out of the cylinder chuck 212 moves to the right as viewed in FIGURE 7 across the unit 118. In order to prevent interference of the parts of the unit 118 with this movement of chuck 212, we operate the conveying units 118 and 120 out of phase with each other. That is, the stripping station of the unit 118 is spaced circumferentially about shaft 130 from that of the. unit 120. We accomplish this by relatively angularly disposing the cam tracks 178 of the unit 118 with respect to the cam tracks of unit 120.

Referring now to FIGURE 5, we have shown the track 178 formed in one of thestationary cam plates 176 of the unit 118. We have indicated the positions of the followers 174 and 198 and have shown a mandrel shaft end 34 in the position in which it is held by the grippers 146 and 154 of unit 118 to permit it to be grasped by the chuck 212 of the assembly 206. In broken lines we have shown the track 224 of a stationary cam plate of the unit 120. The positions of the followers 198 and 174 riding in this cam track are indicated in broken mandrel ends positioned for stripping by the respective units 118 and 120 are spaced circumferentially with respect to shaft 130 by an angle of 45 degrees. This operation of the units 118 and 120 out of phase permits the chuck of assembly 206 to travel across the unit 120 to grasp a mandrel end positioned by unit 118 for stripping and permits the chuck of unit 204 to travel across unit 118 to permit it to grasp the end of'a mandrel positioned by unit 120. Thus, unit 204 disposed adjacent the unit 118 is operatively associated with unit 120 while unit 296 disposed adjacent unit 120 is operatively associated with unit 118. We mount the respective assemblies 294 and 206 on the machine frame, as shown in FIGURE 2, in positions at which they are axially aligned with mandrels positioned by the respective units 120 and 118. In this manner we simultaneously strip mandrels from two tubes of insulation positioned by the respective units.

Referring again to FIGURES 1 to 3, a plurality of drive motors 226 carried by the machine frame drive respective belts 228, each of which drives a shaft 230 rotatably supported in bearings 232 in the machine frame. We mount a respective cutting blade 234 on each of the shafts 230 'for rotation with the shaft. Motors 226 are energized from any convenient source of electrical energy to drive the saws or cutters 234 continuously. The saws 234 are positioned so that as a tube of insulation from which the mandrel has been stripped moves from the stripping station to the discharge station, cutters 234 trim the ends of the insulation.

From the foregoing it will be appreciated that as fluid is supplied to the cylinders 208 of the assemblies 204 and 206, chucks 212 move in opposite directions across the respective units 118 and 120 to grasp the ends of mandrels positioned for stripping by the respective units 120 and 118. As the piston rods 210 reach the limit of their extended position, chucks 212 are supplied with air under pressure in a manner to be described to cause them to grasp the mandrel ends. When the mandrel ends have been grasped, the flow of fluid to the cylinders 208 is reversed to cause the chucks to withdraw the mandrels from the tubes of insulation. When the rods 210 again reach their fully retracted positions, the air is exhausted from the chucks to cause the chucks to release the mandrels which have been stripped from the tubes of insulation.

We provide our machine with means for receiving the mandrels stripped from the tubes of insulation and for feeding these mandrels to return conveyors. Referring now to FIGURES 3 and 6 to 8, a drive motor 236 energized from any convenient source of electrical energy drives a pulley 238 which drives a V belt 240 to drive an adjustable pulley 242 carried by the input shaft of a reducer cone drive 244. The speed at which the input shaft of drive 244 is driven may be adjusted in a manner known to the art by a sheave speed selector 246. Similarly the speed may be adjusted by actuating a speed selector 248 associated with pulley 238 in a manner known to the art. A clutch 250 and brake 252 connect the output shaft of reducer 244 to the input shaft of a gear drive 254 which drives an output shaft 256 rotatably supported in suitable bearings 258, 260 and 262 in the machine frame. A gear 264 carried by shaft 256 for rotation with the shaft drives an idler gear 266 which drives a gear 270 carried by a shaft 272 rotatably mounted in bearings 274 and 276 supported by the machine frame.

The shaft 272 associated with unit 118 carries for rotation with it adjacent its respective ends a pair of arms 278 and 280. We mount arms 278 and 280 on shaft 272 at the midpoints along their lengths and form the ends of the arms with mandrel end receiving notches or slots 282. The shaft 256 which extends across the machine through unit 120 carries the pair of arms 278 and 280 associated with unit 120. From the foregoing descriptionit will readily be apparent that the arms 278 and 280 adjacent the unit 118 carry away mandrels which have been stripped from the unit 120 while the arms 278 and 280 adjacent unit 120 carry away stripped mandrels which come from unit 118.

Referring now to FIGURE 6, a sprocket wheel 284 carried by shaft 276 intermediate the units 118 and 120 for rotation with the shaft drives a pitch chain 286 which engages and drives a sprocket wheel 288 carried by a shaft 290 for rotation with the shaft. Any convenient means such as a hearing or the like rotatably supports shaft 296 in a bracket 29?. carried by the machine frame. A pivot shaft 294 supported in bracket 292 rotatably carries a pair of arms 296, each one of which is associated With a respective unit of the machine. Springs 228 extending between the arms 296 and the bracket 292 normally urge the arms to positions at which cam followers 308 carried by the arms are in engagement with the surfaces of respective cams 302 secured to shaft 290 by keys 304. The diameter of sprocket wheel 288 is approximately half the diameter of wheel 284 with the result that shaft 298 makes two revolutions for each revolution of shaft 272.

When the air supply to the stripper cylinder is reversed in a manner to be described, the solenoids of the clutch and brake 256 and 252 are energized to couple the output shaft of drive shaft 244 to the input shaft of drive 254 to cause shafts 256 and 272 to be driven. As the mandrel is withdrawn from the tube of insulation, the fingers 296 associated with each unit 118 and 120 are moved upwardly to the broken-line position shown in FIGURE 6 to support the mandrel shaft ends remote from the chucks when the mandrels have been completely withdrawn from the tubes of insulation. At the time the air supply to the chucks is exhausted to release the mandrel ends gripped by the chucks and as the pistons associated with the stripper cylinders arrive at their completely withdrawn positions, arms 278 and 230 associated with each unit pick the mandrel ends up from the chucks and from the fingers 296. It is to be understood as will be explained hereinafter, that in the course of each unloading operation shafts 256 and 272 rotate through a half revolution. At the end of an unloading operation each pair of arms supports a stripped mandrel in the slots 282 located at corresponding arm ends. The other slots are positioned to pick up a mandrel during the next unloading operation. Between successive movements of the arms 278 and 280 the empty mandrels carried by the slots 282 in one end of the arms of each pair are picked out of the slots by carriers 306 fixed on the chains of mandrel return conveyors indicated generally by the reference characters 308 and 310. The return conveyors 308 and 310 return the stripped mandrels to the winding machine (not shown) with which our mandrel stripper is associated.

Referring now to FIGURE 7, the drive shaft 130 of our tripper carries for rotation with the shaft a cam 312 adapted to actuate a slider 314 slidably carried in the machine frame. Slider 314 engages a lever 316 pivotally carried by a shaft 318 on the machine frame. The end of lever 316 remote from slider 314- drives a link 320 adapted to actuate a switch 322. Each half revolution of shaft 130 cam 312 actuates lever 316 to close switch .322.

Referring now to FIGURE 11, one form of control circuit which may be used with our mandrel stripper includes respective conductors 324 and 326 connected to the terminals 328 and 330 of a suitable source (not shown) of electrical energy. We connect the solenoid windings 332 and 334 associated with the respective clutch and brake 132 and 134 in parallel with each other in series with a normally closed switch 1R-1 and a normally closed stop switch 336 between conductors 324 and 326. With this series circuit complete, the clutch and brake solenoid windings 332 and 334 are energized to couple shaft 136 to shaft 130 to cause arms 142 and 144 to rotate. When, from a starting point at which 1R'1 is closed, shaft 130 has been driven to position the pairs of strippers 146 and 154, for example, at the stripping station at which they hold a Wrapped mandrel in a position to be stripped and to position the pairs of strippers 148 and 156, for example, at the delivery station at which they deliver a stripped tube of insulation, cam 312 pivots lever 316 through the medium of slider 314 to close switch 322, indicated schematically in FIGURE 11 as lLS. We connect switch 1LS in series with a relay winding 1R. When switch 1L8 closes in the manner described, relay winding IR is energized to open switch 1R-1 to de-ener'gize windings 332 and 334 to uncouple shaft 130 from shaft 136 and to stop the shaft 130.

Energization of winding 1R also closes a normally open switch 1R2 connected in series with a valve solenoid winding S-1 and a normally closed switch 2R-1. Winding S1 is associated with a valve, indicated generally by the reference character 338 adapted in one condition to supply air to the stripper cylinders 208 in a direction to cause the associated rods 210 to move the chucks 212 inwardly of the machine and in the other condition to supply air to the cylinders to move the chucks 212 outwardly of the machine. In the arrangement shown with winding S1 de-energized valve 338 supplies fluid to the cylinders in a direction to cause them to retract the chucks 212. When switch 1R-2 closes in the manner described herein above, winding S1 is energized to operate valve 338 to supply air to the cylinders to move the chucks 212 into the machine.

Energization of winding 1R also closes a normally open switch 1R-3 connected in series with an oven unloader valve winding S-3 and a normally closed switch 2R-2. Winding S3 is associated with a valve, indicated generally by the reference character 340 adapteclin one condition to supply fluid under pressure to cylinder 52 to move rod 60 upwardly as viewed in FIGURE 9 and in the other condition to supply fluid to cylinder 52 ina direction to move rod 50 downwardly as viewed in FIGURE 9. With winding S3 de-energized, valve 340 suppliesfiuid to cylinder 52 in a'direction to move rod 50 downwardly as viewed in FIGURE 9. When switch 1R-3 closes in the manner described winding 8-3 is energized to actuate valve 340 to move rod 50 upwardly as viewed in FIGURE 9 to cause arms 34 and 36 to rotate in a clockwise direction toward an open mold of the oven 19. It is to be understood that the oven drive must be coordinated with the action of cylinder 52 to ensure that a mold towards which arms 34 and 36 move is open.

As the chucks 212 reach the limits of their travel inwardly of the machine one of them momentarily actuates a limit switch 2L8 connected in series with a relay winding 2R between conductors 324 and 326. This actuation of limit switch 2LS energizes winding 2R to close a normally open switch 2R-3 connected in series between the terminal of winding 2R to which switch 2L-S is connected and one terminal of a normally closed 7 switch 3R2, the other terminal of which is connected to conductor 324 to complete a holding circuit for winding 2R. The energization of winding 2R closes a normally open switch 2R-4 connected in series with a normally closed switch 3R-3 and with chuck valve winding S-2 between conductors 324 and 326. Winding 8-2 is associated with a valve indicated generally by the reference character 342 adapted in one condition to supply air under pressure to chucks 212 to cause the chucks to grasp mandrel ends and in the other condition to exhaust the air from the chucks. In the arrangement shown with winding S-2 de-energized, valve 342 is in a condition at which the air is exhausted from the chucks. When switch 2R-4 closes, winding 8-2 is energized to actuate valve 342 to supply fluid under pressure to the chucks to cause the chuck jaws to close on a mandrel end. It will be remembered that at this time the chucks 212 .are at the limit of their movement inwardly of the machine.

Energization of winding 2R also opens switch 2R-2 to de-energize solenoid S 3 to permit valve 340 to reverse the flow of fluid to the oven unloader cylinder 52 remove a wrapped mandrel from the mold.

After a slight delay to ensure that the mandrel ends are firmly gripped by the chucks, switch 2R-1 opens to de-energize winding 8-1 to permit valve 338 to reverse the flow of fluid to the cylinders 208 to cause the chucks to move outwardly of the machine to strip the mandrels from the tubes of insulation carried by the closed pairs of grippers 146 and 148.

We connect a normally open switch 2R5 asociated with winding 2R in series with the parallel connected clutch and brake solenoid windings 344 and 346 associated with the clutch and brake 250 and 252 between conductors 324 and 326. Energization of winding 2R closes switch 2R-5 to energize windings 344 and 346 to cause shafts 256 and 272 to be driven to operate the unloader mechanism of our stripper.

When the chucks 212 approach their fully retracted position, they momentarily close a normally open switch 3L-S connected in series with a relay winding 3R between conductors 324 and 326. Energization of winding 3R in this manner causes switch 3R-3 to open and thus to de-energize winding S2 to permit valve 342 to exhaust the air from the chucks to release the mandrel ends. As the chucks release the mandrel ends the pair of arms 278 and 280 associated with each unit have moved to a position at which they pick up the stripped mandrel from the chucks and from fingers 296. Energization of winding 3R closes switch 3R-1 to complete the circuit of clutch and brake windings 332 and 334 through a selector switch arm 348 in engagement with a contact 350 providing automatic operation. As shaft 130 begins to turn, cam 312 permits switch lLS to open to tie-energize winding 1R to complete the circuit of windings 332 and 334 through switch 1R-1 and to open switches 1R-2 and 1R-3.

Energization of winding 3R also opens switch 3R-2 after a short delay to permit the stripped mandrel removal arms to reach a position at which the removal conveyor can receive the mandrel. The delayed action of switch 3R2 may be provided by any suitable means such as by a dashpot 339. Opening of switch 3R2 interrupts the holding circuit of winding 2R to tie-energize this Winding and permit switch 2R-5 to open to deenergize the windings 344 and 346 of the unloader drive clutch and brake. We so arrange our system that switch 3R-2 does not open until after winding IR is de-energized to open switches 1R-2 and 1R.3 so that windings S-1 and 8-2 will not be energized by the closing of switches 2R-1 and 2R4. It will be remembered that the stripped mandrels are now clear of the grippers so that they do not interfere with movement of the grippers.

In the operation of our control circuit described above the cycles of operationof the machine follow each other automatically. If it is desiredto operate the machine manually, arm 348 may be moved to engage a contact 352 connected in series with a push-button switch 354 which is connected to the terminal of windings 332 and 334 to which switch lR-l is connected. In this manner the shaft 130 may be moved from the position at which cam 312 closes switch 1LS and will complete a half revolution but will not automatically recycle at the end of the stripping and unloading operations. It is to be understood that the spacing of the carriers on chains 78 and 80 and of the carriers on the return conveyors 308 and 310 is such that the operation of these conveyors is synchronized with the operation of the remainder of the parts of the machine.

In operation of our mandrel stripper for mat winding mach nes assuming the parts are in the positions occupied ust after a stripping operation has been completed, windings 332 and 334 are energized to cause shaft to rotate through a half revolution. As the arms 142 and 1-44 move in a clockwise direction, as viewed in FIGURE 3, a tube of insulation from which a mandrel has been stripped has its ends trimmed by cutters 234.

As the grippers 148 and 154 carrying tubes of insulation approach the delivery location, they are actuated to the open position to permit the trimmed tube from which the mandrel has been stripped to fall to be guided to the discharge conveyor 200 by the guide 202. At the same time in the course of a half revolution of shaft 130, the grippers 148 and 156 which initially were open pick up a wrapped mandrel 32 from the conveyor including chains 78 and 80 and carry the mandrel to the location at which the stripping operation takes place. At

, the end of this half revolution of shaft 130 one pair of grippers such, for example, as the initially empty grippers 148 and 156 occupy the position shown in FIG- URE 3 for the grippers 146 and 154. At the same time, the grippers 146 and 154 have moved to a position to pick up a fresh mandrel on the next stepping operation of shaft 130. At the end of this half revolution of shaft 130, cam 312 actuates switch 11.8 to energize winding 1R to open switch 1R-1 to stop drive shaft 130 and to close switches 1R-2 and 1R-3 respectively to energize windings 8-1 and 5-3 to supply air to cylinders 208 to drive chucks 212 inwardly of the machine and to supply air to the cylinders 52 to move arms 34 and 36 to remove a wrapped mandrel from an open oven mold. In this latter operation as arms 34 and 36 move into the mold, latches 62 are camme-d over the mandrel shaft ends 34. When winding S3 is de-energized in a manner to be described, the latches 62 pull the mandrel out of the open mold and as arms 34 and 36 rotate in a counterclockwise direction, as viewed in FIGURE 9, the latches are cammed by blocks 90 to release the mandrel ends to permit them to come to rest on carriers 84 on chains 78 and 80.

When, under the action of fluid supplied through valve 338 the chucks 212 approach the limit of their inward. movement, one of the chucks actuates a limit switch 2LS to energize winding 2R to open the circuit of winding 5-3 to permit the return action of arms 34 and 36 described above. At the same time, switch 2R-4 closes to complete the circuit of winding 8-2 to supply air under pressure to the chucks through valve 342 to cause the chuck jaws to close on the mandrel ends. A short time after switch 2R-4 closes, switch 2R-1 opens to reverse the flow of fluid to cylinders 208 through valve 338 to initiate the withdrawing action of chucks 212. The delayed action of switch 2R-1 may be provided by any suitable means known to the art such as by a dashpot 337. As this takes place, switch 2R5 closes to energize windings 344 and 346 to cause shafts 256 and 272 to rotate. As these arms rotate and at the time the mandrels are fully stripped from the tubes of insulation, fingers 296 are moved by cams 302 to the broken-line position shown in FIGURE 6 to receive the inboard ends of the mandrels. As the chucks completely withdraw the mandrels and approach their outboard limit positions, one of the chucks momentarily actuates a switch 3LS to complete the circuit of a winding 3R to exhaust the air supplied to chucks 212 through valve 342 and to reenergize windings 332 and 334 to cause shaft 130 to rotate. Shortly thereafter, switch 3R-2 opens and after switch 3R3 opens, arms 278 and 280 have moved from the position at which they pick the stripped mandrel from fingers 296 and from the chuck to the position at which they support the mandrel for removal by the return conveyors 308 and 310. The machine then recycles as before.

As is pointed out hereinabove, our machine includes two conveyors such as the conveyor 76 which receive wrapped mandrels 32 from two ovens. These conveyors carry the wrapped mandrels to the mandrel stripper illustrated in FIGURE 3 having two sets of axially displaced arms which are operated out of synchronism as are the conveyors to receive wrapped mandrels from the respective conveyors and to position them for operation of the stripping units 204 and 206. These stripping units likewise are operated out of synchronism so that the unit 206 strips a wrapped mandrel carried by the unit 118 and the stripper unit 204 strips a mandrel positioned between unit 120. These stripper units have associated therewith the stripped mandrel removal mechanism illustrated in FIGURE 6 which has two sections respectively associated with the two stripper units 204 and 206. As the stripper units operate the arms 278 and 280 carry the stripped mandrels to the return conveyors 308 and 310.

It .will be seen that we have accomplished the objects of our invention. We have provided a mandrel stripper for mat winding machines which automatically removes wrapped mandrels from a curing oven, which strips the mandrels from the tubes of insulation, which trims the ends of the stripped tubes and which automatically returns the stripped mandrels to return conveyors. Our stripper permits advantage to be taken of the potential productive capacity of winding and curing machines of the prior art. It permits the formation of finished tubes of insulation from a mat impregnated with uncured resin to the finished product. It greatly reduces the labor and expense involved in forming insulating tubes or ducts.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, what we claim is:

1. Apparatus for receiving mandrels wrapped with tubes of insulation from a conveyor and for stripping said mandrels from said tubes including in combination gripping means movable between an open position and a closed position, means mounting said gripping means for movement between a receiving station adjacent said conveyor and a mandrel stripping station, means responsive to movement of said gripping means from said receiving station to said stripping station to close said gripping means to grip a tube of insulation carried by a mandrel received at said receiving station, and means for stripping said mandrel from said tube of insulation at said stripping station.

2. Apparatus as in claim 1 in which said means responsive to movement of said gripping means is responsive to movement of said gripping means from said stripping station to said receiving station to open said gripping means to release a stripped tube of insulation.

3. Apparatus as in claim 1 in which said gripping means comprises a pair of grippers and means mounting said grippers for movement toward and away from each other and in which said gripping means closing means comprises a stationary carn track, a cam follower disposed in said track and a linkages connecting said cam follower to one of said arms.

4. Apparatus as in claim 1 in which said stripping means comprises a chuck adapted to be actuated to grasp a mandrel end, means mounting said chuck for movement toward and a way from a tube of insulation carried by said gripping means at said stripping station and means for actuating said chuck.

5. Apparatus as in claim 1 including a removal conveyor and means for transferring a stripped mandrel from said stripping means to said removal conveyor.

6. Apparatus as in claim 1 including means for trimming an end of a stripped tube as said gripping means moves from said stripping station to said receiving station.

7. Apparatus for receiving mandrels wrapped with tubes of insulation from a conveyor and for stripping said mandrels from said tubes including in combination respective pairs of grippers each movable between an open position and a closed position, means mounting said pairs of grippers in spaced relationship for movement between a wrapped mandrel receiving station and a stripping station, the arrangement being such that with a first pair of said grippers at said stripping station the other of said pairs occupies a position in advance of said receiving station, means for stripping the mandrel from a tube of insulation at said stripping station, means for stepping said gripper mounting means to move said first pair of grippers from said stripping station to said advance position and to move said other pair of grippers from said advance position to said stripping position and means responsive to movement of said pairs of grippers for opening said first pair of grippers to release a tube of insulation from which the mandrel has been stripped and for closing said other pair of grippers to grip a tube of insulation carried by a mandrel received at said receiving station.

8. Apparatus as in claim 7 in which said stripping means comprises means for grasping the end of a mandrel to be stripped and means for moving said mandrel end grasping means toward and away from a tube of insulation at said stripping station and in which said apparatus includes means for supporting the end of a mandrel being stripped remote from the end engaged by said grasping means as said mandrel being stripped is withdrawn from its tube.

9. Apparatus as in claim 7 including a discharge conveyor adapted to receive stripped mandrels, a pair of spaced arms the ends of which are adapted to receive mandrel ends and means for moving said arms to receive a stripped mandrel from said stripping means and for moving it to a position at which it may be picked up by said discharge conveyor.

10. Apparatus for receiving mandrels wrapped with tubes of insulation from respective conveyors disposed in side-by-side relationship including in combination a pair of mandrel stripping units, each of said units comprising gripping means movable between an open position and a closed position, common means for mounting the gripping means of the respective units for movement from a respective wrapped mandrel reeciving station to a respective stripping station, respective means for stripping mandrels from tubes of insulation at the respective stripping stations, said stripping stations being displaced from each other and means responsive to movement of the gripping means for opening and closing the gripping means.

11. Apparatus as in claim 10 in which said gripping means opening and closing means comprise respective cam tracks and means mounting said cam tracks in angularly spaced relationship.

12. Apparatus for stripping a tube of material from an elongated mandrel having ends including in combination a frame, a pair of clam-ps adapted to engage andhold a tube carried by a mandrel, means mounting said clamps on said frame for movement from an open position to a closed position at which they hold a tube, means adapted to be actuated to grasp a mandrel end, means mounting said grasping means on said frame for movement from a' remote position to a position adjacent a mandrel end, means for moving said grasping means from said remote position to said position adjacent a mandrel end and means responsive to arrival of said grasping means for actuating said grasping means to grasp a mandrel end.

13. Apparatus as in claim 12 including means for returning said grasping means to said remote position after actuation thereof to grasp a mandrel end.

14. Apparatus for separating a tubular casing from a mandrel upon which it has been formed and to which it is frictionally adhered, including a station for receiving and holding in a definite position a mandrel and a casing carried on the mandrel, clamps adapted to grip the casing received with a mandrel in the station, a carriage reciprocable toward and away from said station, a chuck mounted on the carriage and movable therewith axially in line with the mandrel, jaws on the chuck radially and outwardly movable to an open position, a withdrawn position of the carriage wherein the chuck is spaced [from the mandrel a distance at least equal to the length of the mandrel, an actuator advancing the carriage toward the mandrel, a stopping device terminating the advancing movement of the carriage with the open jaws of the chuck over the end of the mandrel, means reactive to the termination of the advancing movement of the carriage to cause the jaws to close and seize the end of the mandrel and to initiate the return of the carriage to its withdrawn position, said return of the carriage drawing the mandrel from the casing, the latter being retained in the station by the clamps, and means motivated by the return of the carriage opening the jaws and freeing the mandrel and releasing the casing from the grip of the clamps.

References Cited by the Examiner UNITED STATES PATENTS 1,916,361 7/1933 Curtiss 29234 X 2,025,030 12/ 1935 Ford 182 2,551,260 5/1951 Carwig 205-24 2,604,658 7/ 1952 Broden 1 82 2,979,765 4/ 1961 Stephens 186 3,127,024 3/ 1964 McPherson 29-234 X RICHARD H. EANES, JR., Primary Examiner. 

14. APPARATUS FOR SEPARATING A TUBULAR CASING FROM A MANDREL UPON WHICH IT HAS BEEN FORMED AND TO WHICH IT IS FRICTIONALLY ADHERED, INCLUDING A STATION FOR RECEIVING AND HOLDING IN A DEFINITE POSITION A MANDRAL AND A CASING CARRIED ON THE MANDRAL, CLAMPS ADAPTED TO GRIP THE CASING RECEIVED WITH A MANDRAL IN THE STAION, A CARRIAGE RECIPROCABLE TOWARD AND AWAY FROM SAID STATION, A CARRIAGE MOUNTED ON THE CARRIAGE AND MOVABLE THEREWITH AXIALLY IN LINE WITH THE MANDRAL, JAWS ON THE CHUCK RADIALLY AND OUTWARDLY MOVABLE TO AN OPEN POSITION, A WITHDRAWN POSITION OF THE CARRIAGE WHEREIN THE CHUCK IS SPACED FROM THE MANDREL A DISTANCE AT LEAST EQUAL TO THE LENGTH OF THE MANDREL, AN ACTUATOR ADVANCING THE CARRIAGE TOWARD THE MANDREL, A STOPPING DEVICE TERMINATING THE ADVANCING MOVEMENT OF THE CARRIAGE WITH THE OPEN JAWS OF THE CHUCK OVER THE END OF THE MANDREL, MEANS REACTIVE OF THE TERMINATIN OF THE ADVANCING MOVEMENT OF THE CARRIAGE TO CAUSE THE JAWS TO CLOSE AND SEIZE THE END OF THE MANDRAL AND TO INITIATE THE RETURN OF THE CARRIAGE TO ITS WITHDRAWN POSITION, SAID RETURN OF THE CARRIAGE DRAWING THE MANDRAL FROM THE CASING, THE LATTER BEING RETAINED IN THE STATION BY THE CLAMPS, AND MEANS MOTIVATED BY THE RETURN OF THE CARRIAGE OPENING THE JAWS AND FREEING THE MANDREL AND RELEASING THE CASING FROM THE GRIP OF THE CLAMPS. 